Regulation of contractility in the teleost heart

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This NSERC program of research addresses the mechanisms by which the strength of the heart beat is regulated in fish. Although our primary interest is the salmonids which include rainbow trout, sockeye salmon and steelhead, other fish which function in warmer waters (e.g. zebrafish and tilapia) will be studied for an evolutionary perspective. The salmonids are of great importance socially, economically and strategically in Canada. How hearts from fish function is of great interest physiologically because their aquatic habitat exposes them to sudden and challenging changes in water ion concentrations (including Ca and Na), water temperature and pH that are not experienced by mammals in their terrestrial environments. Thus a major objective in this program of research is to understand how the environmental differences have dictated the molecular design of the hearts of these organisms. Another major objective is to understand how environmental changes (e.g. temperature and pH) acutely impact the basic regulatory mechanisms in the teleost heart on a molecular and cellular level, thereby impacting cardiac contractility. Cardiac contractility is quite variable but is regulated on a beat-to-beat basis by the amount of calcium (Ca) delivered to the contractile element and/or the sensitivity of the contractile element to Ca. Thus this program of research will focus on the structure and function of specific proteins in the cells that make up fish heart that regulate calcium delivery and removal and the contractile response to these signals. We will use techniques from bioinformatics, molecular biology, confocal microscopy, biophysics and physiology.